Manchester United manager Louis Van Gaal declared his side back in the title race following his fourth consecutive win over Liverpool.

Despite being under pressure all season, the Dutch coach has a 100 per cent record against United’s bitterest rivals since he moved to the Premier League.

He said the 1-0 win, secured by Wayne Rooney, could have a galvanising impact on his side in the second half of the season.

“We have a lot of matches still to go. We started 2016 very good with a lot of wins, this game will give a big boost to the players and the fans and the environment of Manchester United,” said Van Gaal.

“To beat Liverpool is always important. Today it was important because our competitors have lost points. I don’t know how the result will go in the Arsenal game but maybe a lot will depend on this.”

After so much flak and pre-match emphasis on the repercussions of defeat, this represented one of Van Gaal’s most satisfying afternoons of the season, even if he accepted the performance was flawed.

“There are matches we have played much better in and from that perspective I can’t say it is a good day because Liverpool dominated in the first half,” he said.

“I don’t think it was our best day of the season. You have to see it always in perspective. Of course, for the fans, for me and the players it is a fantastic win and it will give us a boost. Maybe from that perspective it is our best day.”

United’s win did not match some of the flamboyant Anfield games of the Sir Alex Ferguson era, stealing the three points after a turgid contest between two sides a pale imitation of the respective line-ups a matter of years ago, let alone previous generations.

David De Gea’s saves from Adam Lallana, Jordan Henderson and – most impressively – Emre Can gave United the platform for victory.

Van Gaal did not believe De Gea was particularly stretched, however.

“That is why he is our goalkeeper. He is always reaching a very high level,” said Van Gaal.

“But I cannot say that today he has done a lot. He has stopped the balls that he had to stop. Maybe there was one save with one hand? Maybe. But I think he has to save it. I think a goalkeeper has to do it. I demand it. That is why he is playing for Manchester United.”

For Rooney, it was an especially sweet strike – the second time he has scored the winning goal at Anfield in a United shirt.

He now has 176 United Premier League goals - more than any player has managed for one club since the top flight seceded from the Football League.

"I scored the winning goal at Anfield and it has been a long time since that happened for me - my first year at United - so I will be a bit selfish today and enjoy that more than most,” said Rooney.

“This is a special feeling, obviously. It is always great to score at your rivals and, against Liverpool for this football club, it is a massive result. On a personal note it doesn't get much better. Obviously it's great to have records but I don't think that'll beat the feeling I've got now.”

Like Van Gaal, Rooney hopes United will use the result as a catalyst for a sequence of victories.

"I think everyone knows the importance of this game, regardless of positions," he said.

"It is a massive game for both football clubs, for the fans and it was a great victory. It's three points we needed to continue this start to the year. It's a massive victory for us.”

Man of the match De Gea added: “They had some chance but we defended really well. After that, Wayne scored a fantastic goal. I hope that victory gives us a lot of confidence and hopefully we can get three or four wins in a row. That is what we want.”